Find Middle of a Linked List - Leet code 876 - two pointers approach

Hey everyone, we will solve how we can find the Middle of the Linked List and solve this problem using a pointers approach.

Step 1: Initialize Pointers

We are going to initialize the left and right pointers at the beginning of our beginning of our Linked List.

left = head  # Start both pointers at the head
right = head

Step 3: Traverse through the linked list

In this step, we will traverse through the list by moving the right pointer by two steps and the left pointer by one step. When the right pointer reaches the end (null), the left the pointer will be in the middle.

Step 3: Once the loop terminates, the left the pointer will be at the middle node.

def find_middle(head):
    # Step 1: Initialize left and right pointers at the head
    left = head
    right = head

    # Step 2: Traverse the linked list, moving left by 1 step and right by 2 steps
    while right and right.next:
        left = left.next         # Move left one step
        right = right.next.next  # Move right two steps

    # Step 3: Left is now pointing to the middle of the linked list
    return left

Time and Space Complexity:

• Time Complexity: O(n)

• Space Complexity: O(1)

Video Explanation:

Thanks, everyone hanging in there till the last ❤️ and I'll see you in the next one!!